Tesla Motors Inc (TSLA): Confusing Changes In Vehicle Power Ratings

Tesla Motors Inc (NASDAQ:TSLA) revealed the ‘D’ in a recent event, which was nothing but the All-Wheel-Drive Model S vehicle. During the introduction of dual-motor Model-S vehicle, another change happened in Tesla’s website for horsepower ratings of single-motor Model S vehicles. This change has puzzled many and a ‘Green Car Reports’ article threw some light on the issue.

Tesla Motors Inc (NASDAQ:TSLA) has launched three versions of single-motor Model S vehicles since 2012. Single-motor Model S vehicles, 65kWh, 85kWh and P85 performance versions had a listed power rating of 302hp, 362hp and 416hp (225kW, 270kW and 310kW) respectively.

Tesla Motors Inc (NASDAQ:TSLA) made some modifications to the website configurator in order to add the dual-motor Model S vehicle, but something strange has happened in the website during the process. The single-motor Model S power ratings were increased in the website configurator overnight. The updated single-motor Model S vehicles, 65kWh, 85kWh and P85 performance versions had a listed power rating of 380hp, 380hp and 470hp (283kW, 283kW and 350kW) respectively.

Many assumed that the motors were upgraded in the single-motor Model S vehicles as well, but in spite of the power ratings increase, no changes were made to the 0-60mph acceleration time and top speed in the website. This raised many eyebrows and casted doubt over the power boost on paper mentioned by Tesla Motors Inc (NASDAQ:TSLA).

Clearer investigation revealed that no changes were made to the single-motor Model S vehicles. Only change that happened was Tesla Motors Inc (NASDAQ:TSLA)’s way to describe the vehicle horsepower. Original power ratings were the numbers for motor-inverter-battery combination, whereas the new numbers are simple measure of maximum motor power. The older method reveals the actual performance of vehicles, and a traditional method too, but the new method does not account for losses encountered in the inverter and battery.

In the older method 65kWh and 85kWh models had different power ratings even though they had the same motor. This was mainly due to the fact that 85kWh had lower losses across inverter and battery. But in the new ratings both 65kWh and 85kWh has same power ratings, which does not reveal the actual performance of the vehicles.

Tesla Motors Inc (NASDAQ:TSLA) has taken these concerns into consideration and started working to update their website with clear definition of net power and motor power for its vehicles.